Example Code for Arduino - Get WiFi Weather Infromation

Hardware Preparation

FireBeetle 2 ESP32-S3 AI Board with OV2640 Camera x 1

Software Preparation

Other Preparation Work

Before burning the code, please perform the following steps

Install the Arduino_JSON library. Enter Arduino_JSON in Arduino IDE Tools -> Manage Libraries and install the library
Register an OpenWeather account to get the weather information you want. Go to https://openweathermap.org/appid/, and create an account.
Click My API Keys to enter the interface for obtaining API
Copy the key here (this key is your only key to get weather information from OpenWeather)
You can fill the Key into the following URL and fill in the city name and country to get the city weather information.

http://api.openweathermap.org/data/2.5/weather?q=yourCityName,yourCountryCode&APPID=yourAPIkey

For example, fill in Chengdu in yourCityName, CN for yourCountryCode, fill in yourAPIkey which is the API key obtained earlier, the following is the URL of Chengdu, China with the API added:

http://api.openweathermap.org/data/2.5/weather?q=ChengDu,CN&APPID=4de305d0a52ddaceaecba50a757e9968

Copying your URL into your browser will return a set of information corresponding to your local weather. On the day this tutorial was written, we had the following information about the weather in Chengdu, China.

Sample Code


/*
This example gets weather information
*/

#include <WiFi.h>
#include <HTTPClient.h>
#include <Arduino_JSON.h>

//Modify WIFI name and password
const char* ssid = "******";//WIFI name
const char* password = "******";//WIFI password

//Fill in the API Key you got
String openWeatherMapApiKey = "4de305d0a52ddaceaecba50a757e9968";
//Example:
//String openWeatherMapApiKey = "4de305d0a52ddaceaecba50a757e9968";

// Fill in your city name and country abbreviation
String city = "ChengDu";
String countryCode = "CN";

//Example：
//String city = "ChengDu";
//String countryCode = "CN";

//Set the interval for obtaining information, the following is used for testing, so it is set to 10 seconds
//You should limit the minimum interval of accessing time according to the upper limit of the number of times to access the data within the specified time period of the website you need to obtain the data.
unsigned long lastTime = 0;
//Set to get weather data every 10 minutes
//unsigned long timerDelay = 600000;
//Set to get weather data every 10 seconds
unsigned long timerDelay = 10000;

String jsonBuffer;

void setup() {
  Serial.begin(115200);
  WiFi.begin(ssid, password);
  Serial.println("Connecting");

  //Determine if WIFI is connected
  while(WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
  Serial.println("");
  Serial.print("Connected to WiFi network with IP Address: ");
  Serial.println(WiFi.localIP());
  Serial.println("Timer set to 10 seconds (timerDelay variable), it will take 10 seconds before publishing the first reading.");
}

void loop() {
  //Send HTTP to get request
  if ((millis() - lastTime) > timerDelay) {
    //Check if WIFI is connected
    if(WiFi.status()== WL_CONNECTED){
      String serverPath = "http://api.openweathermap.org/data/2.5/weather?q=" + city + "," + countryCode + "&APPID=" + openWeatherMapApiKey;

      //Put the combined URL into the httpGETRequest function to get the text through HTTP get request.
      jsonBuffer = httpGETRequest(serverPath.c_str());
      Serial.println(jsonBuffer);

      //Store the parsed Json object value in the Jsonu buffer
      JSONVar myObject = JSON.parse(jsonBuffer);

      //Determine if the parsing was successful
      if (JSON.typeof(myObject) == "undefined") {
        Serial.println("Parsing input failed!");
        return;
      }

      Serial.print("JSON object = ");
      Serial.println(myObject);
      Serial.print("Temperature: ");
      //The obtained temperature is actually Kelvin.
      //Kelvin = Celsius + 273.15
      double c = myObject["main"]["temp"];
      c = c-273.15;
      Serial.println(c);
      Serial.print("Pressure: ");
      //myObject["main"]["pressure"], the front is the content of the quotation marks before {}, and the latter is the data to be read in quotation mark
      Serial.println(myObject["main"]["pressure"]);
      Serial.print("Humidity: ");
      Serial.println(myObject["main"]["humidity"]);
      Serial.print("Wind Speed: ");
      Serial.println(myObject["wind"]["speed"]);
    }
    else {
      Serial.println("WiFi Disconnected");
    }
    lastTime = millis();
  }
}

String httpGETRequest(const char* serverName) {
  WiFiClient client;
  HTTPClient http;

  //Connect URL
  http.begin(client, serverName);

  //Send HTTP site request
  int httpResponseCode = http.GET();

  //This array is used to store the obtained data
  String payload = "{}";

  //Put the obtained data into the array
  if (httpResponseCode>0) {
    Serial.print("HTTP Response code: ");
    Serial.println(httpResponseCode);
    payload = http.getString();
  }
  else {
    Serial.print("Error code: ");
    Serial.println(httpResponseCode);
  }

  //Release resources
  http.end();

  //Return the obtained data for Json processing
  return payload;
}

Result

Other Supplementary Information

Member function

httpGETRequest(serverPath.c_str());
- Description: Parse the obtained object
JSON.typeof(myObject)
- Description: Determine whether the object is in a parsed format